No I haven't because I am not sure what it does. I ran accross this
command but could not find much documentation about it. Will this
have an effect on the other kernels (including ones I will still
compile)?
TIA
Bram

man depmod

[...]

I'm no expert but it seems to suggest it acts only on the running kernel
unless you specify a different module directory.

I had read the manpage but was hoping to find some more documentation
about this subject...
Anyway I ran depmod and rebooted and everything works fine, thanks!
Still: is there no general documentation on how modules are loaded and
how this can be configured in debian?

Did you figure out what depmod did to make the reboot find the module?

Not really, it appears to have added a line to the modules.dep file.
But I haven't found much information on the use of this file yet.
Regards
Bram

Yes, that's too bad. I am in the same boat. With the modules I use,
everything works (TM) but how come?